Tube formation for structuring heatexchanger core-units



March 8, 1966 F. M. YOUNG 3,239,002

TUBE FORMATION FOR STRUCTURING HEATEXGHANGER CORE-UNITS Filed Jan. 6, 1964 FIGI FIG 3 H FIG 4 "')."I" I I F| 9 INVENTOR.

05 m .Ol8 .095 cEj FEE} BY ATT Y United States Patent 3,239,002 TUBE FORMATIGN FOR STRUCTURING HEAT- EXCHANGER CORE-UNITS Fred Matthew Young, Racine, Wis., assignor to Young Radiator Company, Racine, Wis., a corporation of Wisconsin Filed Jan. 6, 1964, Ser. No. 335,885 3 Claims. (Cl. 165-134) Vibration is the bane of the heat-exchanger industry in its production of large-size radiators required for the cooling systems of high-powered heat engines. Heat engines of the diesel type, currently in extended use, range from 25 HP. to 2500 HP. These engines require radiators capable of reducing the engine coolant from a temperature of 200 F., as it leaves the engine jacket, to 190 F. as it reenters the engine jacket.

The accepted structuring of such radiators involves a battery of closely-spaced, thin-metal tu-bes spanning and supporting opposed header plates and mounting closelyspaced, thin-metal fins throughout the space between the header plates. The header plates are integrated with or attached to upper and lower tanks. Preferably, the tubes are of narrow, elongated cross-section measuring between 0.095 and 0.160 of an inch in thickness and between 0.500 and 0.750 of an inch in width. In length the tubes may range from 1 to 8 feet. Radiators of this kind may range in size from 1 to 8 feet in height and from 1 /2 to 6 feet in width for use with power units for mobile equipment and from 2 to 6 feet in width and from 2 to 9 feet in height for use with power units for stationary equipment.

The power units for either type of equipment may be operating at speeds from 200 rpm. to 2500 rpm. inevitably such speeds create a terrific amount of vibration. Such vibration, communicated to the radiators, all too frequently create leaks in the radiators. Such leaks are caused, generally, by breaks in the tubes where the tubes are bonded to the header plate, due to the temperatures, pressures and vibrations to which this type of radiator is subjected along the small-radius lateral portions of these flat-type tubes.

The possibility of remedying this problem is foreseen in the 'hereinshown forming of these tubes with extra thickness along the small-radius lateral portions.

The main objects of this invention are; to provide an improved tube formation for use in structuring core-units required for certain types of heatexchangers; and to provide an improved, fiat-tube formation which, upon being incorporated into a heat-exchanger core-unit, can withstand the excessive vibration, to which the core-unit will be subjected in use, without the likelihood of breaks occurring in the tubes at their bonded junction with the header-plates of the core-unit.

In the accompanying drawings:

FIG. 1 is a reduced-sized, perspective of a type of heat-exchanger the core-unit for which is structured with tubes embodying this invention;

FIG. 2 is a fragmentary, perspective view of one end of a core-unit structured with tubes embodying this invention;

FIGS. 3 and 4 are enlarged, cross-sectional end views of two slightly different for-ms of tubes embodying this invention;

FIGS. 3A and 4A are side elevational views of ends of the tubes shown in FIGS. 3 and 4, respectively;

FIG. 5 is an enlarged, end view of one of the punchedflanged tube holes in the header plates of the type shown in FIG. 2;

FIG. 6 is an enlarged, fragmentary view taken on the plane of the line 6-6 of FIG. 2;

Patented Mar. 8,1966

FIG. 7 is a transverse, sectional view taken on the plane of the line 7-7 of FIG. 6; and

FIGS. 8 and 9 are views similar to FIGS. 3 and 4 but showing dimensions for tubes for a heat exchanger of the more average construction measuring 3 feet wide and 4 feet high.

The essential concept of this invention involves tubes, of elongate-d-cross-section contour, the opposite smallradius lateral portions of which are materially thicker than the intermediate and substantially parallel portions.

The tubes 11 embodying the foregoing concept and as herein shown, are of elongated, cross-sectional contour having the substantially-parallel, thin-walls 12 integrated with the materially-thicker small-radius lateral portions 13. A battery of such tubes 11, in closely-spaced and parallel relationship, span and are bonded at their ends in the usual manner to header plates 14 to comprise a core-unit 16. Between the header plates 14 and embracing the battery of tubes 11 are a series of the conventional, thin-metal fins 15 firmly bonded to the tubes. Such a core-unit 16 mounts upper and lower tanks 17 and 1 8 on the respective header plates 14, and is set within a supporting frame 19 to complete the heat exchanger or radiator, as it often is designated in the industry. The tanks 13 and 19 have the conventional coolant inlet 21 and outlet 22, respectively.

As indicated in the several figures of the drawing, the small-radius lateral portions 13, of these tubes 11, are thickened materially over that of the side walls 1 2. Such a thickness as a rule would be approximately between two and three times the thickness of the side walls 12. For special types of core units 16, the tubes 11 would have these thickened lateral portions reinforced by inwardly-projecting ribs 24.

For a more average size of core-unit 16, structured With tubes 11 of such formation, measuring 3 feet wide and 4 feet high, the tubes 11, of either form, might be dimensioned approximately as indicated in FIGS. 8 and 9.

The header plates 14, as herein shown, are of a type that have staggered rows of the flanged openings 23 for the reception of the ends of the tubes 11, the general nature of these flanged openings 23 is shown in FIG. 5.

The sealing of these joints of the tubes and header plates can be accomplished by either of two conventional methods; melting a solder wire laid on the header-plates around the tubes, or dipping the header-plates, with the tube-s in place, in a solder bath.

For an average size core-unit 16, as above mentioned, the flanged openings 23 in the header plates 14 would be approximately 0.100 inch long and 0.745 inch wide at the upper edges of these flanges.

Core-units of the type indicated in FIG. 1, and of the dimensions above stated, during production are subject to varying temperatures needed to effect the bonding of the tubes to the header plates 14. Moreover, in use, these tubes 11 are subject to strains from greatlyfluctuating ope-rating temperatures and excessive vibration.

The bonding and use temperatures tend to alter the physical character of the metal, particularly its grain size. The operating vibrations tend to focus strains on these thin-metal tubes at the peripheral areas of the bonding thereof to the perimeters of the flanged openings 23 of the header plates 14.

It is this combination of high temperatures and excessive vibration that, in the core units with tubes of the same thickness throughout their contour, create breaks in the tubes 11 along the small-radius lateral portions. The increased thickness of these lateral portions, as herein shown and explained, provide the tubes 11 with such an increased resistance as to greatly reduce if no preclude their breaking under these excessive heat and vibration strains.

Variations and modifications in the details of the structure and arrangement of the parts may be resorted to Within the spirit and coverage of the appended claims.

I claim:

1. A heat-exchanger core unit, for use in cooling systems for high-powered heat engines in equipment subject to excessive vibration and high temperatures, comprising, a pair of header plates having a prearranged series of tube openings of elongated contour wherein the defining walls of the tube openings are parallel and the ends are semi-circular, and a plurality of parallel thinmetal tubes of subustantially fiat, elongated cross-sectional contour the opposite sides of which are parallel and of uniform thickness and the exterior transverse width of the tube is substantially one-seventh the exterior transverse length of the tube, the tubes having their ends inserted in the header-plate openings and bonded thereto, the tubes having their small radius lateral portions materially thicker than the intermediate parallel side portions to insure the tube-header bonding to the header 20 plates against fracturing under the strains of service.

References Cited by the Examiner UNITED STATES PATENTS 527,680 10/1894 Gilchrist 165-177 1,929,365 10/1933 M'aut-sch 165-77 FOREIGN PATENTS 479,542 2/1938 Great Britain. 865,653 4/1961 Great Britain.

ROBERT A. OLEARY, Primary Examiner. A. W. DAVIS. Assistant Examiner. 

1. A HEAT-EXCHANGER CORE UNIT, FOR USE IN COOLING SYSTEMS FOR HIGH-POWERED HEAT ENGINES IN EQUIPMENT SUBJECT TO EXCESSIVE VIBRATION AND HIGH TEMPERATURES, COMPRISING, A PAIR OF HEADER PLATES HAVING A PREARRANGED DEFINING WALLS OF THE TUBE OPENINGS ARE PARALLEL AND THE ENDS ARE SEMI-CIRCULAR, AND A PLURALITY OF PARALLEL THINMETAL TUBES OF SUBSTANTIALLY FLAT, ELONGATED CROSS-SECTIONAL CONTOUR THE OPPOSITE SIDES OF WHICH ARE PARALLEL AND OF UNIFORM THICKNESS AND THE EXTERIOR TRANSVERSE WIDTH OF THE TUBS IS SUBSTANTIALLY ONE-SEVENTH THE EXTERIOR TRANSVERSE LENGTH OF THE TUBE, THE TUBES HAVING THEIR ENDS INSERTED IN THE HEADER-PLATE OPENINGS AND BONDED THERETO, THE TUBES HAVING THEIR SMALL RADIUS LATERAL PORTIONS MATERIALLY THICKER THAN THE INTERMEDIATE PARALLEL SIDE PORTIONS TO INSURE THE TUBE-HEADER, BONDING TO THE HEADER PLATE AGAINST FRACTURING UNDER THE STRAINS OF SERVICE. 